As part of a restructuring plan it announced four months ago, Merck said it will eliminate 50 jobs at a site in Springfield that it gained through a merger with Schering-Plough.

In a notice filed with the state Department of Labor earlier this week, Merck said the job cuts would go into effect on Dec. 20.

The notice did not describe the type of jobs Merck is cutting at the Lawrence Road office site, and Ron Rogers, a spokesman for the drug maker, said the company would not provide specific details about the functions being eliminated.

After Merck’s $41.1 billion acquisition of Schering-Plough in 2009, the company said it would cut about 17 percent of its global workforce of nearly 115,000. In July, after reducing its employees around the world to 91,000, Merck said its job cuts would have to go deeper — by an additional 13,000 positions, many of which would be administrative.

The Springfield cuts represent part of those cuts, Rogers said.

Last year, Merck announced it would be closing three properties it had acquired from Schering-Plough — in Lafayette, Roseland and Union.